The first dietary guidelines for Americans were published in the year 1977, almost at the exact same time the obesity epidemic started. Of course, this doesn't prove anything (correlation does not equal causation), but it makes sense that this could be more than just a mere coincidence.

Since the guidelines were published, many massive studies have been conducted on the low-fat diet. It is no better at preventing heart disease, obesity or cancer than the standard Western diet, which is as unhealthy as a diet can get (37, 38, 39, 40).

For some very strange reason, we are still being advised to follow this type of diet, despite the studies showing it to be completely ineffective.